(1) About an operation apparatus equipped with a fail-safe function
As a kind of an operation apparatus of a horizontal blind, one is known in which an operation cord is suspended from a pulley supported by a head box so as to be capable of rotating, and raising or lowering operation and angle-adjusting operation of slats are performed through operations of the operation cord.
In such a horizontal blind, the pulley is supported on a front surface of one side of the head box so as to be capable of rotating and the pulley is covered with a pulley case. When the operation cord suspended from the pulley is operated, the pulley is rotated and a driving shaft is rotated based on a rotation of the pulley by way of a gear box within the head box.
When the driving shaft is rotated, a bottom rail is raised or lowered by way of a lifting cord so as to raise or lower the slats. Also, the slats are rotated by way of a ladder cord.
In the above-mentioned horizontal blind, the endless operation cord is sometimes caught on a dweller or a household item, so that their behavior is unduly restricted. Therefore, an operation apparatus is proposed in which, when the operation cord is pulled with a greater force than an operation force applied in usual operations, the pulley is caused to drop off from the head box, so that the movement of the dweller is not hindered.
Patent document 1 discloses an operation apparatus which is equipped with a fail-safe function where, when an excessive downward pull force is applied to the operation cord, the pulley and the pulley case are caused to fall, so that hindrance of behavior of a dweller due to an accidental catch of the operation cord is prevented.
(2) About a case in which a horizontal blind is arranged in a bath room.
Conventionally, when a horizontal blind is arranged in a bath room, since it is not possible to fix an attaching bracket for supporting a head box on a wall surface by means of a screw, a fixing apparatus that fixes the head box between opposed wall surfaces has been in practical use.
Patent document 2 discloses a fixing apparatus where a moving shaft is provided to an end portion of a head box so as to be capable of protruding and receding, a protrusion length of the moving shaft from the end of the head box is adjusted by a rotational operation of a dial, so that the head box is provisionally held between wall surfaces, and subsequently, the moving shaft is forcibly pressed against the wall surface by a rotational operation of an operation lever so as to fix the head box between the wall surfaces.
In such a horizontal blind, raising or lowering operation and angle-adjusting operation of slats are performed by operating a ball-chain (operation cord) suspended from an end of the head box supported between the wall surfaces.
(3) About a roll-up blind
In a roll-up blind, a top end of a screen is attached to a head box, and a bottom end of the screen is attached to a weight bar of a round bar shape. A lifting cord for raising and lowering the screen is attached, at one end thereof, to a back surface of the head box, and, at another end thereof, to a winding shaft within the head box so as to be capable of being wound up, via a position below the weight bar. The weight bar is supported by the lifting cord which is wound around a lower part thereof.
When the winding shaft is rotated by an operation apparatus, the lifting cord is wound up around the winding shaft, so that the weight bar moves up while winding up the screen. When the winding shaft is rotated to wind off the lifting cord from the winding shaft, the weight bar moves down while winding off the screen.
Patent document 3 discloses a roll-up blind where a chip-blind is used as a screen.